1. Field of the Invention
This invention relates to a package for the storage of a plastic medical container. More particularly, this invention relates to a package for the storage of a plastic medical container such as a blood bag or a transfusion solution bag which contains therein a medicinal fluid.
2. Description of Prior Arts
Plastic medical containers such as blood bag and transfusion bag contain therein anticoagulants such as ACD solution and CPD solution which serve to prevent the blood from being coagulated during collection or transfusion of blood. The medical containers containing such chemical solution are stowed in tightly closed containers of synthetic resin designed exclusively for the purpose of storage. Since the medical containers are made of plastic materials and therefore are pervious to gases, there is a possibility that oxygen gas, for example, will penetrate through these containers and pass into the chemical solutions contained therein to cause oxidative degradation of the chemical solutions. The wetting components, particularly the moisture, present in the chemical solutions penetrate through the walls of the containers and add to the humidity within the packages. If aerobic microorganisms survive by some reason or other within the chemical solutions, there ensues an inevitable possibility that microorganisms, which collect on the surface of the containers between the time these containers are manufactured and the time they are put to use will gain in growth because of the heightened humidity.
It has been recently proposed to place a deoxidizer tightly closed containers to effect quick fall of the concentration of oxygen within the tightly closed containers and prevent the contents of the containers from oxidation. As a tightly closed container suited to the proposed prevention of its contents from oxidation, there has been proposed a bag-shaped container which is obtained by vacuum depositing aluminum on the opposed surfaces of two superposed polyester type resin sheets and heat sealing the corresponding peripheries of the two sheets through the medium of a hot melt type adhesive agent (Japanese Published Unexamined Patent No. SHO 53(1978)-113693). Since the bag-shaped container is deficient in a shape-retaining property, the inner volume of the container decreases and the walls of the bag sink as the oxygen therein is gradually absorbed by the deoxidizer. When the contents held in the container and the walls of the container adhere fast to the surfaces of the deoxidizer, the absorption of oxygen by the deoxidizer fails to proceed at the expected rate and the concentration of oxygen in the container fails to fall to the prescribed level (less than 0.1%/50 hrs), frequently with the result that microorganisms which by chance have found their way into the containers in the course of fabrication will enjoy growth in the presence of oxygen. Further, the bag-shaped container has an inferior shape-retaining property, it tends to inconvenience various handling works for storage. When such bag-shaped containers are piled up during storage or in transit, they collapse and bring about adverse effects upon their container contents. When the container is molded threedimensionally, since the conditions involved in the molding deform and crack the conventional barrier layers formed of aluminum, for example, to intercept gases and steam, the container is destitute of a gas barrier property.
As a deoxidizer, a powdered deoxidizer which is composed of a metal such as iron and a halogenated metal has been known. Such a deoxidizer is used as contained in a bag-like container previous to gases. As the deoxidizer absorbs oxygen, the metal used therein gathers rust. Particularly when the metal happens to be iron, it rusts in red. The red rust exudes through the walls of the bag-like container, comes into contact with the medical container and soils it. To eliminate this problem, a membrane impervious to gases is attached to one of the walls of the aforementioned bag-like container. This bag-like container is used with the membrane side thereof facing the medical container held in the package. When the gas-impervious membrane side of the bag-like container is directed toward the medical container, the gas-pervious wall side thereof comes into contact with the bottom surface of the package. Consequently, the overall area of the package in which the interior of the package is exposed to contact with the ambient gas is notably decreased. Because of the heavy decrease of contact area, it becomes no longer possible to lower the concentration of oxygen within a stated length of time to a prescribed level, namely to an oxygen concentration of not more than 0.1% by volume within 72 hours, the very conditions tolerated for the prevention of growth of aerobic microorganism. Thus, the interior of the package cannot be brought to a substantially oxygen-free condition. The package, therefore fails to keep the medical container held therein from growth of aerobic microorganism and other defiling causes.
It is, therefore, an object of this invention to provide a novel package for the storage of a medical container. Another object of this invention is to provide a package for the storage of a medical container holding therein a medicinal fluid, which package is capable of retaining its interior in a substantially oxygenfree condition and preventing it from growth of aerobic microorganism.